Process of and apparatus for cracking oils



e. L. HOXIE. PROCESS OF AND APPARATUS FOR CRACKING OILS,

APPLICATION FILED AUG .9, I918.

Patent-ed June a, 1922.

2 SHEETSSHEET I.

n Co/wE/vsms flux/marry STILL G. L. HOXIE.

PROCESS OF AND APPARATUS FOR CRACKING (ms.

APPLICATION FILED AUG-9. I918.

1,418,718. PatentedJune 6, 1922.,

2 SHEETS-SHEET 2.

To all 'wlwm'it may concerh:

' GEQB-G-E I. HOXIE, OF UPPER MONTGLAIR, NEW J PRQCESS OF AND lAIEPARATUS FOR dRACKING: OILS,

i mi Be it known that I, GEORGE L. HoxIE, a citizen of the UnitedStates, and a. resident of U per Montclair, in the county of Essex andfate of New Jersey, have invented certain new and useful Improvements inProcesses of and Apparatus for Cracking Oils, of which the followingis-a full, clear, concise, and exact description, such as will enableothers skilled inthe art to which the invention relates to make and usethe same, reference being made therein to the accom panying drawings,which form a part of this specification.-

My invention relates to v the treatment of liquid hydrocarbons such, forexample, as petroleum in the crude form in which it is obtained from theearth, or after a part of the more volatile'constituents thereof havebeen removed therefrom by fractional dis; tillation; the object of saidtreatment or process being to increase; the amount of sirable liquidhydrocarbons, such for examlighter and more volatile'hydrocarbonsobtained from a given quantity of crude or partially refined petroleumor crude oil. In processesv of the class to which my invention relatesthe liquid hydrocarbon is heated to a comparatively high temperature,which results in the decomposition or breaking up of some of the.constituents of the hydrocarbon-being treated,.after which the volatileproducts thus produced are collected and condensed; such processes beingcommonly referred to as cracking? processes, the purpose of which isto'increase the'yield of the more volatile products, such as gasoleneand similar light hydrocarbons, obtainable from a given quantity ofcrude petroleum'orsimilarliquid hydrocarbon.

, The -object s of my inyention are toprovide an improved processormethod of treatment, and an improvedapparatus or devic suitableforperforming the said proc' ess, whereby, the quantity of light 'liquid;hydrocarbons, that is, those boilmg below to,

fixed boiling pointa'ssu-med as the" maxi-mum boiling point desirable,obtainable from a given quantity of. crude oil is materially in--creased; to provide an improved method and I Specification ofLettersB'atent. Patented June 6, 1922; Application filed August 9, 1918, Serialno. 249,077.

for storage or convenientuse on the other,

is reduced toa minimum; to provide an imapparatus in which theproduction of un'd'e-I ple as those boiling at a temperature the highfor eficient use [in an internal combusproved process and means forworking the same which may be operated continuously, which may bereadily controlled, and one in which the product produced will be ofuniform quality so long as the operation of the process is continued; toprovide a process which may be readily and cheaply carried out, and anapparatus for convenientlyand' with facility performing the process; andto provide other improvements in and relating to the processes commonlyknown and referred to as cracking processes for increasing the yield ofthe lighter liquid hydrocarbonsmbtainable from a given quantity of crudepetroleum. 1 In cracking processes heretofore in use the usual practicehas been to heat the entire mass of liquid hydrocarbon being operatedupon to a high temperature, that is to a temperature which, fromexperience, has been found to increase the yield, of liquid hydrocarbonswhich boil at a comparatively low temperature, as in the case ofgasolene, and then separate the light or more volatile hydrocarbons fr0m. the mass ofhydrocarbon thus treated,

As distinguished above outlined, my improved process contemplates theheating to a temperature sufficient to accomplish the cracking of theliquid hydrocarbon operated upon of a small volume of said liquid,and-then adding said small quantity of heated and more orlesscomple'tely cracked hydrocarbon to a muchlarger volumeof'comparatively cool liquid hydrocarbon and mixing the same,- therewith; whereby the heated liquid is suddenly cooled, the crackingaction'is entirely or for the most part'arrested, and the small volumeof liquid hydrocarbon subjected to the ac- "tion ofthe 'lreat togetherwith such volatile products as may have resulted from such heating-arerapidly: dispersed throughout a largefmass of similar liquid at a muchlower temperature.

-,The temperature of the larger volume of liquid hydrocarbon is keptsubstantially lower than' the temperature best suited for cracking theliquid being operated upon;

and the said larger massfin the carrying-out from the old processes a ofmy process in its preferred form, and by means of the preferred form ofapparatus provided for that purpose, and after the process is inoperation; is made up of fresh untreated liquid hydrocarbon, of liquidhydrocarbon which has been subjected to a cracking temperature but thevolatile products thus produced not separated therefrom, and of heavierliquid hydrocarbon the residue left after drivin off the more volatileconstituents from previously heated liquid, and which residue is beingcontinually worked over.

It therefore follows that in the carrying out of my improved processsmall quantities of liquid hydrocarbon are being continually heated to acracking temperature and that said small quantities are immediately, andwithout attempting to separate the more volatile products thus producedtherefrom, added to and mixed with and more or less dispersed throughouta much larger volume of liquid hydrocarbon maintained at'a much lowertemperature; there being no attempt to separate the light or volatilehydrocar bons produced by the heating from the identical volume ofliquid subjected to the cracking temperature as by distilling them offat or substantially at the cracking temau perature, and under suchconditions as to pressure as'may be necessary in order to accomplish thedistillation of such light hydro- .carbons at the inordinately hightemperature required for the most eifective cracka at ing of the liquidbeing operated upon.

The particular mass of liquid subjected to the cracking temperature, orrather continual succession of small masses so treated has justpreviously been heated to such a temperature such that it vwas beingcracked or decomposed into more volatile products arrests the crackingoperation, and the uncrackedportion of the liquid in question as well asthe lighter or cracked products produced by the heating become mergedwith and dispersed throughout the larger mass of cooler hydrocarbonwhile the lighter products are in a nascent state or condition,

as it were, and before they have separated, to as vapors or otherwise,from the heated liquid from which they were formed. After this coolingand'mixingstep or operation the said light and volatile products aredriven oil or distilled from the total volume 5 or liquid hydrocarbonproduced by mixing This sudden cooling of the liquid which a above theboiling point of the lighter hydrocarbons produced in carrying out theprocess, whereupon they will obviously pass off from the mixture in theform of a vapor which may be condensed by any suitable condenser. Iprefer, however, to withdraw the mixture produced as above from themixing receptacle and subject the same to a dis tillation process in aseparate still; in which case the cracking of the liquid hydrocarbon andmixing the same with a large volume of cooler similar liquid, and theseparation of the lighter hydrocarbons from the mixture thus produced,are separate and distinct steps, and are carried out by separate anddistinct parts of the apparatus provided for the performance of myprocess. In either case the process is a continuous one, for the highlyheated and cracked constituent is being continuously added to the largermass of cooler liquid hydrocarbon, thus producing a mixture whichcontains, and from which the lighter and more volatile hydrocarbons maybe separated. The actual separation of such light products by adistillation process is or may be continuous in the case where suchprocess is carried out in the receptacle in which the mixing occurs, andby the inherent heat which the mixture attains when the process has beenin operation for a while; and the distillation step is or may likewisebe made continuousif the mixed liquid is withdrawn from the mixingreceptacle and distilled in a separate distilling apparatus.

Various particular forms of apparatus may be employed in performing myim proved process, some of which are illustrated in the drawingsaccompanying and forming a part of this specification; althoughit willbe appreciated ithat forms of apparatus other than those illustrated maybe employed, so long as they are suitable for use in performing thevarious steps or operations in which my improved process consists.

In the said drawings Figure 1 is a view showing in a conventional manneran apparatus in which the heating of the relatively small quantity ofliquid hydrocarbon is accomplished by means of a plurality of gas heatedheating devices located within the receptacle containing the relativelylarge volume of liquid hydrocarbon, this view being a section taken upona plane'indicated by the line 1- -1,'

Figure 2;

Figure 2 is a View showing a sectlon taken upon a plane indicated by theline 2-2, Fi ure 1;

igure 3 is a view showing a-conventional form of'apparatus in which theheating of the relatively small volume of liquid hydrocarbon to crackthe same is provided for by the use of a furnace located outside thereceptacle containin the relatively large volume of liquid by rocarbon;

Figure 4 is a view illustrating a form of apparatus in which the heatingof the por tion of the liquid hydrocarbon which is cracked isaccomplished by the use of an inductive electrical heating-device; v

Figure 5 is a View similar to Figure 3, but showing a modified form ofheating means;

Figure 6 is a'view showing in a conventional manner an apparatus inwhich the heating is accomplished by an electrically heated resistanceelement located within the receptacle containing the larger volume ofliquid hydrocarbon with which the heated liqluid hydrocarbon is mixed;and,

igure 7 is a view showing a conventional form of apparatus inwhich theliquid hydrocarbon being heated, as well as that with which the heatedportion is mixed is in the form of a spray, the heating being accom-'plished by an electrically heated resistance element.

Referring now to the drawings, and first to the form of my inventionillustrated in Figures 1 and 2 thereof, the reference numeral 10designates a suitable receptacle or container of any desired form; thesame being designed to contain the liquid hydrocar bon operated upon inthe performance of my process, and of large capacity as compared withthe amount or volume of liquid hydrocarbon being heated at any giventime to a cracking temperature.

Located within the'receptacle or container 10 is a plurality of heatingmembers, each designated as a whole by the reference numeral 11, wherebythe small portion of the liquid hydrocarbon which is heated to such atemperature as to crack it in performing my process is heated to acomparatively high temperature, to thereby crack the liquid thus 7heated, and decompose the same into liquid hydrocarbons having alower-boiling point thanthat of the original liquidhydrocarbon subjectedto my process. lt will be obvious, however, that a greater or lessnumber of vheating elements than the number illustrated may be employed,as my invention is in no way concerned with a particular number ofheating devices employed in a given apgaratus.

ach of the heating devices above referred to is shown as made up of ametallic tube 12 arranged in an inclined positionand extend- ,as will beappreciated.

ing from one side to the other of the receptacle 10, within which tube aheating ele ment in the form of a gaseous fuel'burner 13 is located, tothereby heat the tube, as will a v be appreciated, a suitable outletflue or chimney 14 being provided at the upper end-of each tubularmember through which the products of combustion may pass. Sur-.

rounding, the tubes 12 are tubes 15 made, preferably, of non-conductingmaterial, such as porcelain, fire clay, or similar material; which outertubes are spaced apart somewhat from the metallic tubes 12 to therebyprovide an annular heating space 16 between the two tubes. Provision ismade for the flow of a stream-of liquid hydrocarbon from, the main bodyof liquid contained in, the receptacle l0'into the annular space between the two tubes, along or through said space, and out therefrom andinto the main body of'liquid hydrocarbon; so that a'continuouscirculation of the liquid being thus heated to a cracking temperaturewill be form of my invention illustrated by openings 17 provided in theouter tube and located, adjacent the lower end thereof, and throughwhich the cool liquidmay flow into the annular space, and other openings18 located adjacent the'upper end of the tube and through which" theheated liquid may flow from the said space and return to the main bodyof liquid within the receptacle 10.

It will therefore be appreciated that when the device is in operationand the tube 12 is being heatednas above explained, a continuous flow ofthat porti on of the liquid hydrocarbon being treated which at anyparticular instant is being heated to a cracking temperature, will flowfrom the main body or mass of liquid contained in the receptacle 1O lntothe annular space between the tubes 'maintained; this being provided forin the 12 and 15, upwardly through and along the passage between saidtubes, and out from between said tubes at the upper ends thereof;whereupon the liquid whichis thusheatQ ed returns to the main body ofliquid and.

will be such as to produce the largest pos- A sible quantity of theparticularly light hydrocarbons which it is desired to produce,

The portion of the liquid flowing through the annular space 16 which isactually cracked by the heating action to which it is subjected in theperformance of my process, as well also as the portion of the saidliquid which in practice is notactually cracked, re

turn to and mix with the main body of the liquid hydrocarbon in thereceptacle 10, the

posed to radiation, and to which a fresh supply of cool liquid iscommonly being supplled continuously or frequently; (and the use of theouter tube 15 of non-conducting material whereby the heat generatedwithin and conducted to the exterior of the metallic tube 12, and to theliquid hydrocarbon flowing through the annular space 16, is notcommunicated or conducted to the main body of liquid, obviouslycontributes to the keeping of the main body of liquid at a comparativelylow temperature; The main body of liquid within the chamber 10, may, iffound necessary, be cooled and its temperatur thereby more positivelyregulated and kept materially below the temperature of the portion ofthe liquid which is being heated by the heating devices, by the use ofseparate and independent cooling means provided for that purpose; as itis obvious that the continuous mixing of the liquid which is heated tothe cracking temperature with that in the receptacle. 10 will cause thetemperature of the latter to rise, and that such temperature might, ifuncontrolled, rise to too high a point.

It therefore follows that the cracked products produced by the heatingmembers are carried away from the zone at which heating and crackingoccurs by the stream of heated liquid, and that the uncracked portion ofthe heated liquid as well as the portion thereof which is cracked by theheat to which it is subjected are immediately mixed with the main bodyof cooler liquid within the chamber 10 while the cracked products are ina nascent state, and before they have hadtime to vaporize and becomefree of or to separate from the uncracked portion of the heated liquidwith which they are associated; the said products being thus condensed,dissolved in, reabsorbed into, or otherwise incorporated with anddispersed throughout the much larger body of relatively cool hydrocarboninto which the heated liquid enters and with which it mixes. 1

This mixing of the heated constituent of the liquid operated upon withthe cooler main portion thereof, and the consequent cooling of the saidheated portion to a temperature below the cracking temperature to whichit was subjected, arrests the cracking action and prevents decompositionof the cracked products, or over cracking, or the continuation of thecracking action after it may be desirable to terminate the same. Thecracking action is thus controllable in my process, and may be regulatedand varied in such a way as to secure uniformity in the product obtainedto a greater extent than has heretofore been the case; furthermore, theprocess may be regulated with reference to and in such away as toproduce cracked products having definite and predeterminedcharacteristics, for the properties of the cracked roducts depend uponthe temperature emp oyed', the duration of the heating action or rate offlow of the stream of liquid being heated, and other circumstances allof which are under the control of the operator.

The main body of liquid hydrocarbon within the receptacle 10 obviouslybecomes more or less heated after the rocess has been in operation for atime, alt ough as stated the temperature of said liquid is alwaysmaterially below the temperature to which the small portion of liquidseparated or differentiated from the main body thereof is heated tothereby crack the same. This heating of the main body of liquid willobviously result in the vaporization of some of the lighter and morevolatile'hydrocarbons produced, which action, however, will rapidlybuild up a pressure within the receptacle 10 above the liquid therein,which will arrest such action and prevent the further vaporization ofthe cracked products produced.

In certain cases I find it desirable to subject the liquid within thereceptacle 10 to a gas pressure other than that due to the vaporizationof cracked products produced, and reater than the vapor tension of theliquid containedtherein at the temperature of the said liquid, to whichend I have illustrated a tube 19 leading, from a reservoir 20 containing.a liquefied gas or a gas compressed to a high pressure, to thereceptacle 10 and discharging thereinto above the surface of the liquid,whereby the liquid hydrocarbon within the receptacle 10 may be sub-'jected, to a as under pressure derived from the recepta e 20; the gasemployed preferably being nitrogen, carbon di-oxide, hydrorovides also1,418,713 Y I r other characteristics ofthe said products are in thecontainer to gas pressure as above at the wbeginningof the process,after which and when the body or liquid within the receptacle has becomeheated, the supply of gas from the container 20 may be disco-ntinued',the pressure to prevent the vaporlzation of the cracked products beingthere-- after maintained by the vaporization of a small portion of thelighter and more volatile v as 'hereinbefore -jecting the same to a-which process may be carried'on iicts produced in the operation ofmyprocp be. conducted in the receptacle of the said products.

It will be appreciated that after my improved process has been inoperation for a time the body of liquid hydrocarbon within. thereceptacle 10 will contain the cracked products which have been thus farproduced, explained, the amount of such products withinthe mass ofliquid being obviously dependent upon the length of I time the processhas been in operation, and the temperature to which the liquid flowingpast the heated device hasbeen heated; or,

as otherwisestated, upon the degree or extent'of cracking produced bythe heating means. These light or volatile products will be removed fromthemass of liquid by subdistillation process, either in the receptacle1001- in a still separate and distinct from the said receptacle. Thedistillation may be fractional whereby cracked products having differentboiling points are separated from one another, or all said productsboiling above a predetermined temperature may be collected as a singleliquid.

In case the distillation of the volatile prodess is to I 10, suchdistillation will preferably be ,ac-

' complished bythe heat of the mass of liquid process and whichare-contained in the. said I Ordinarily I I I I cracked liquidproducts-from the condenser,

containedwithin the receptacle; it being'ob- I jvious that the said massof liquid will, after .the process haslbeen in operation for a time,have become'heated to-a thecracke-d hydrocar temperature above theboilin point of bons pro ucd in the performance of the liquid; Indistilling in accordance withthis scheme it is only;necessary toprovide. an outlet conduit" 21' 1 leading from the receptacle 10, whichconduit .is cooled by a con- I denser-QQyWhereb-y the vapors of thecracked hydrocarbons driven off from the main body of'diquid arecondensed and a liquid cracked product thereby secured,'said condu1t 21be-' .ing preferably provided with'a valve 221 for controlling the flowtherethrongh and regu lating the pressure within thereceptacle" 10. "thedischarge-' of condensed or the flow of vaporfrom the receptacle -io,

will be regulated and restrained by means of a suitable ressureregulating valve; in

f orderto there y increase the back pressure leading to a still 24 ofany suitable form and construction, and within whichthe liquid isdistilled;'the lighter hydrocarbons passing from the still through aconduit'25 controlled at itsoutlet end by a valve 251, and thesameloeing condensed by a cooler 26 as in ordinary distilling andcondensingop- I erations. As a matter of racti-ce I prefer to use bothmethods of distillation at one and the same time, as it is moreconvenient and in other respects advantageous to con-. duct such of thecracked products as are vaporized under the temperature and pressureconditions present in the receptacle 10 therefrom through a conduitcontrolled by a pressure regulating valve to thereby control thepressure within the said receptacle, and condense the said'products bymeans of a cooler like the cooler 22; while at the same time providingfor the removal of liquid from the receptacle 10, which liquid obviouslycontains. cracked products which are not vap rized under thetemperature, conditions existing in the said receptacle, into a separatestill like the still 24 wherein they may be subjected to a differenttemperature than that of the main'body of liquid within the receptacle10, 1

Itwill be appreciated ,thatmy improved process is a continuous one inthat cracked roducts are being continuously produced by the heatingmemberor device, and continuously added to the main body of liquidwithin the receptacle 10, thus "providing a mass or' body of liquidcontaining cracked covered. i a I The cracked" products may in whole orin ipart be permitted to flow as vapors and continuously from thereceptacle 10 through the.

v products and from which they may berei which case it follows that the;cracking of a massv of liquid introvduced' into the container may'becontinued or carried on until the residue isof such a character that itmay no longer be cracked; because of the fact that the residueori-uncracked part ferentiated portion of the liquid flowing through theannular space 16 ata givenin- "stant ma jaga1n flow8thro gh said. spaceas been" returned' -to andm'ixed after it with the'main body of'liquid,andafter the cracked products'produced in the said po tion-havefbeenseparated therefrom. 3

of any particular dif- I prefer, however, to provide for the supply offresh and untreated liquid hydrocarbon to the receptacle 10, to whichend asupply pipe 27 leads thereinto through which fresh liquidhydrocarbon. may be supplied; and, in order to insure that the liquidwill be effectively subjected to the action of each of the severalheating devices, I preferably provide baffle plates 28 within thereceptacle 10 for causing the liquid to flow past the several heaters 11in succession. When operating with a constant or substantially constantsupply of fresh and untreated liquid hydrocarbon, as will usually be thecase, the process and apparatus will be so regulated that the residuefrom the still 24 will-be a heavy hydrocarbon having a high boilingpoint, and one which it is not desirable to subject anew to a crackingprocess.

In the form of apparatus illustrated in Figure 3, a receptacle 28similar to the receptacle 10- is provided for containing the. mass ofliquid hydrocarbon operated upon. Communicating with this receptacle isa heating loop made up of metallic pipes 29, 30, 31 whereby acirculation of liquid hydrocarbon from the receptacle 28 through saidpipes and back to the said receptacle, is maintained; which pipes passthrough and are heated by a suitable furnace 32 so that the heating isaccomplished by heating means located outside of the receptacle whichcontains the liquid being operated upon. In this form. of apparatus theliquid hydrocarbon is supplied to the receptacle through a conduit 33which communicates with an equalizing chamber 34 to which liquidhydrocarbon is suplied by a pump 35, and into which chamber a conduit 36leading from a source of gas under pressure discharges; and by means ofwhich =devioe liquid hydrocarbon may be supplied under pressure to thesaid receptacle 28. The

heating tubes preferably contain deflectors.

37made of non-conducting material, such as porcelain, the purpose ofwhlch is to cause the liquid being heated to-flow adjacent the wall ofthe tubes whereby the liquid is more effectively heated.

Figure 4 shows a form of apparatus in which the heating of the portionof liquid hydrocarbon subjected to the cracking operation isaccomplished by means of a loop 38 made of hollow piping and the ends ofwhich communicates with, a receptacle 39 containing the liquidhydrocarbon being treated, and the ends of which loop are alsopreferably connected by an independent conductor 40 whereby the loop andconductor form a secondary coil, madeup of a single turn, of atransformer; the iron core of which is indicated at 40 andtheprimarycoil of which is shown at 41. .It therefore follows that upon passing analternating current through the primary 41, the secondary made up of thepipe 38 will be heated to a high temperature by induction, thusproviding for the cracking ofthe liquid hydrocarbon flowing through thesaid tube. Figure 5 shows a form of apparatus in which the heating ofthe liquid hydrocarbon subjected to the cracking temperature isaccomplished by means of a gas heated furnace 42 in which a loop 43 islocated,'and the ends of which loop communicate with the receptacle 44which contains the main body of liquid hydrocarbon being treated.

Figure v6 shows a form of apparatus in which the heating of the liquidis accomplished by means of an electrical heater 45 located within thereceptacle 46, said heater being shown as made up of an outer tube 47,an inner core 48 and a tubular resistance member 49 spaced apart fromboth said last mentioned members whereby annular passages are provided;and which resistance member is heated electrically by a current ofelectricity conveyed thereto through an insulated terminal 50 and asecond terminal 51 connected with the wall of the receptacle, one end ofthe heating element 49 being connected with the wall .of the receptacleas shown at 52. The members 47 and 48 are made of insulating materialinorder to prevent short circuiting, and to also. provide heatinsulation whereby the heating of the liquid within the receptacle 46,except by the mixture therewith of the portion of theliquid csubjectedt0 the cracking temperature, is avoided. t

Figure 7 shows a form of apparatus in .which the liquid hydrocarbon isin a finely divided. form during the heating of the portion thereofwhich. is subjected to the cracking temperature, and when the heated andcracked products thus produced are mixed with the larger volume ofunheated liquid. In the apparatus there illustrated the hydrocarbonbeing subjected to my process passes from a chamber 53 through an outletconduit 54 having a nozzle or rose at its lower end, whereby the liquidis finely divided and a spray produced, said rose being located in aclosed chamber 56. Located be low the nozzle 55 is a heater 57 which maybe in various forms, but which is here shown as an electric heater, thesaid heater being in the path of the finely divided or sprayed liquidissuing from the nozzle or rose 55. Such being the case it will beobvious that the portion of the sprayed liquid closely adjacent theheater 57 will beheated to a high temperature and cracked, while theportion thereof more remote from the heater will not be subjected tosuch heating and era cking operation. Both the heated and cracked, andthe unheated liquid pass downward through the chamber 56 and becomemixed with one another at the lower portion there? 30 heating-device;and that the liquid hydroof where they accumulate, and from whichchamber they pass through conduit 58 into a receiving receptacle 59. Thea product which collects in this last mentioned receptacle is obviouslymadeup of a small volume of liquid hydrocarbon which has been highlyheated and a portion of which has been cracked, together with a largervolume of liquid hydrocarbon which has not been subjected to thecracking temperature, the

' same as in the case of the receptacles in the.

various forms of apparatus heretofore de-; scribed, and the temperatureof which mix- .ture is obviously low as compared with the tem erature towhich the smaller portion of the iquid hydrocarbon is heated during thecracking step. This mixed liquid hydrocarbon is withdrawn from. thereceptacle 59 through a conduit- 60 and treated to a distillationprocess in any suitable-still, as hereinbefore explained.

In view of the premises it will be appreciated that in the working of myimproved process the entire mass or body of liquid hydrocarbon withwhich the process is concerned at any given time may properly beregarded as made up of two parts, the

' greater of which within the receptacle 10 is many times'the volume ofthe lesser part being heated to a cracking temperature by the I -assumethat state, because of the high temimme iatelly 55.

perature employed for cracking the liquid;

but no attempt is made to separate them from "such liquid as may not becracked .while they are in the nascent state in which the mustnecessarily exist at or immediate y after the instant that they.areproduced. On the contrary, the said gaseous or incipiently gaseousproducts are pre vented from separating, physically, from theli uid fromwhich they are produced by discharging both the cracked. and uncrac edheated liquid into'the greatly excess volume of cooler liquid, wherebythe cracked products are, before they have had an o portunity toseparate as aigas or vapor, con ensed and absorbed into and become;dispersed throughout the greater mass ofcomparatively coolliquid; thecracked volas tile products being subsequently recovered performed uponthe entire mass thereof, as

'from the large volume. of liquid in which they are absorbed by adistillation process distinguished from keeping or attempting to keepthe cracked products inthe gaseous or vaporousform in which they areproduced,

collecting them in that state and finally condensingthe vapor.

The pressure to which the liquid hydrocarbon operated upon is preferablysubjected prevents the cracked and volatile products from separatingfrom the liquid from which. they are produced until the mix ing of saidliquid with the larger body of liquidhas been consummated, restrains thevaporization of the cracked products and determinesthe temperature atwhich they will be driven ofl from the mass'of liquid throughout whichthey are dispersed, and

determines the character of the cracked products resulting from theheating action as the properties of the said products depend upon thetemperature and concomitant pressure conditions present at the placewhere the cracking occurs. The process may therefore be controlled andregulated both as to the purely physical phenomena associated therewithand as to the character or properties of the cracked products producedby regulating'the pressure to which the liquid hydrocarbon operated uponis subiected;

The temperature to which the small volume of liquid which is beingcontinuous heated while it is separated from the main mass of liquid isheated will be a temperature suflicient to accomplish the cracking of 7i the hydrocarbon being treated, and will vary'both with the characterof the liquid being treated and the character'or boiling point of theproduct desired. As a general average a temperature of 650 degrees Fahrenheit .or upward will accomplish the cracking. of most hydrocarbons,and will produce a product sufiiciently volatile to. take the place .ofor be used with ordinary gasdlene.

It will be appreciated, however, that the temperature of the main bodyof liquid never rises to the cracking temperature. Its

volume is large as compared with that of the liquidbeing hracked, andthe liquid being cracked -.is heated under c0nd1t1ons designed tominimize'the direct commumca .tion of heat to the main mass of liquid.

The main body of liquid is to be sure heated by the small volume ofcracked hydrocarbonf dischargedthereinto to accomplish the suddencooling of the cracked p'or'-.

'tion, but as hereinbefore pointed out the temperature of the mainvolume is kept substantially lowerthan the temperature best {suited forcracking the hydrocarbon operated upon. "A- temperature of 650 F. orabove will ordinarily be used to accomplish to the crackingtem-peraturytthe tempera- ---ture of the main mass should be kept asl'ow,

' the cracking of the small volume subjected as possible, as the processis the more effective the more sudden the cooling of the cracked portiondischarged into the main mass of liquid undergoing treatment; andthetemperature of the main mass of hydro- 1 carbon ought to be kept atleast 250 or 300 degrees Fahrenheit below the cracking temperature. i

It will be appreciated that whereas a high temperature is commonlynecessary to accomplish the cracking of a liquid hydrocarbon, thetemperature at which the resulting product vaporizes is very much lower,in fact several hundred degrees lower in most cases. My process takesadvantage of this fact and avoids, and in fact prevents to as great anextent as possible, the heating of the entire mass of liquid beingtreated up to the cracking temperature, as has heretofore commonly beenthe case; thus providing a process wherein the cracking is accomplished\by the heating of a small isolated and continuously renewed mass ofliquid, which' to be sure is heated to the cracking temperature, but inwhich the main body or mass of liquid being treated is kept at atemperature several hundred degrees below the cracking temperature. I

Having thus described and explained my invention, I claim and desire tosecure by Letters Patent:

1. In a device for cracking liquid hydrocarbons, a closed receptacle ofrelatively large capacity adapted to contain a liquid hydrocarbon;heating means located within said receptacle; means for causing a streamof liquid hydrocarbon of relatively small volume as compared with thevolume of liq,-

uid contained within said receptacle to flow from the body of liquidcontained therein past said heating means, and backinto the relativelylarge mass of liquid contained within said receptacle; a source of gasunder pressure; a conduit leading from said source and discharging intosaid receptacle to thereby create a gas pressure therein, and controlthe vaporization of the cracked products present in the liquid withinsaid receptacle; and means whereby the liquid hydrocarbon not heated asaforesaid is maintained in a relatively cooled condition.

2. The carbon which consists in heating a relatively small quantity ofliquid hydrocarbon to a temperature sufficient to crack the same;

mixing said heated liquid immediately, and without separation of thelighter products produced by such heating therefrom, with a relativelylarge quantity of liquid hydrocarbon the temperature of which ismaintained throughout such heating operation at a tem-v peraturesubstantially below the temperature to which the small quantityof liquidhydrocarbon is subjected; and removing the rocess of treating liquidhydro tively large volume of liquid hydrocarbon;

isolating a'relatively small quantity of said liquid hydrocarbon;heating the small volume of liquid hydrocarbon thus isolated to atemperature sufiiciently high to crack the same; discharging the saidheated liquid into the large body of liquid aforesaid below the surfacethereof immediately, and without separation of the lighter productsproduced by such heating therefrom; maintaining the temperature of saidlarge body of liquid'materially below the temperature to which saidsmallvolume of liquid hydro carbon is heated; and removing the lighterproducts from the mixture .thus produced by distilling thesaid mixture.

4. The process of treating liquid hydrocarbpn which consists inproviding a relatively large volume of liquid hydrocarbon; continuouslyremoving relatively small uantities of said liquid hydrocarbon from t emain body thereof; continuously heatin the liquid hydrocarbon thusremoved an while it is isolated from ,the main body of liquidhydrocarbon to a temperature sufliciently high to crack the same;continuously Rreturning' the heated'liquid hydrocarbon to the main bodyof liquid hydrocarbon at a point below the surface thereof; maintainingthe temperature of said large body of liquid materially below thetemperatureto which said small quantities ofliquid hydrocarbon areheated; and subjecting the said mixture to a distilling ."pro c ess tothereby separate the lighter hydrocarbons produced liquid hydrocarbon toa temperature suih- I 'ciently high to crack the same; continuuouslyreturning the heated liquid hydrocarbon at a-point below the surfacethereof; keeping said small quantities of liquid are'heated; andsubjecting the said mixture to a distilling process to thereby separatethe lighter hydrocarbons produced by the heating step aforesaidtherefrom. q

6. The process which consists in providcarbon to the main body of liquidhydro-W the temperature ofsaid mixture substantially belowthetemperature to which ing a relatively large mass of liquidhydrocarbon; isolating a relatively small' uantity of said mass ofliquid hydrocarbon eating mass of liquid hydrocarbon not heated asaforesaid at a temperature substantially lower than the temperature towhich said small quantity of liquid hydrocarbon is heated.

7. The process which consists in providing a relatively large mass ofliquid hydrocarbon; isolating a relatively small quantity of said massof liquid hydrocarbon and heating the same to a cracking temperature;discharging the heated liquid into the large mass of liquid aforesaidbelow the surface thereof immediately, and without separation of thelighter products produced by said heating action therefrom; continuouslyreplacing the liquid heated as aforesaid by liquid derived from saidrelatively large mass of liquid; and maintaining said relatively largemass of liquid at a temperature below that to which said relativelysmall mass is heated.

8. The process which consists in providing a relatively large mass ofliquid hydrocarbon; isolating a relatively small quantity of said massof liquid hydrocarbon and heating the same to a cracking temperature;permitting a movement of the heated liquid into the large mass of liquidaforesaid below the surface thereof immediately, and without separationof the lighter products produced by said heating action therefrom;continuously replacing the liquid heated as aforesaid by liquid derivedfrom said relatively large mass of liquid; maintaining said relativelylarge mass of liquid at a temperature below that to which saidrelatively small mass is heated; and subjecting said large mass ofliquid to a gas under pressure to thereby restrain the evaporation ofvolatile products therefrom.

9. The process which consists in providing a relatively large mass ofliquid hydrocarbon; isolating a relativelysmall quantity of said mass ofliquid hydrocarbon and heating the same to a cracking temperature;discharging the heated liquid into the large mass of liquid aforesaidbelow the surface thereof immediately, and without separation of thelighter products produced by said heating action therefrom; continuouslyreplacing the liquid heated as aforesald by liquid derived from saidrelatively large mass of liquid; maintaining sa1d relatively large massof liquid at a temperature below that to which said relatively smallmass is heated; subjecting said larger mass of liquid to a gas underpressure; and subjecting the mixture produced by the continual dischargeof the heated liquid containing cracked products into the larger mass ofliquid to a distilling operation, to thereby separate the, lighterproducts from the said mixture.

10. The process which consists in providing a relatively large mass ofliquid hydrocarbon; isolating a relatively small quantity of saidmass-of liquid hydrocarbon and heating the same to a crackingtemperature: discharging the heated liquid into the large mass of liquidaforesaid below the surface thereof immediately, and without separationof the lighter products produced by said heating action therefrom;continuously re. placing the liquid heated as aforesaid by liquidderived from said relatively large mass of liquid; maintaining saidrelatively large mass of liquid at a temperature below that to whichsaid relatively small mass is heated; and distilling the mixtureproduced by the continual discharge of the heated liquid containingcracked products into the larger mass of liquid by means of the heatthus acquired by said larger mass, to thereby separate the lighterproducts from said mixture.

11. The process which consists in providing 'a relatively large mass ofliquid hydrocarbon; isolating a relatively small quantity of said massof liquid hydrocarbon and heating the same to a cracking temperature;discharging the heated liquid into the large massof liquid aforesaidbelow the surface thereof immediately, and without separation of thelighter products produced by said heating action therefrom; continuouslyre- 1M5 placing the liquid heated as aforesaid by liquid derived fromsaid relatively large mass of liquid; maintaining said relatively largemass of liquid at a temperature below that to which said relativelysmall mass is we heated; subjecting said larger mass of liquid to a gasunder pressure; and distilling the mixture produced by the continualdischarge of the heated liquid containing cracked products into thelarger mass of no liquid by means of the heat thus acquired by saidlarger mass, to thereby separate the lighter products from said mixture.

In testimony whereof, I have signed my name to this specification this7th day of 11st August, 1918. l

GEORGE L. HOXIE.

